A 74-year-old patient initially presented with a primary rectal tumor underwent abdomino-perineal resection in 2025. Adjuvant chemotherapy was not administered due to deranged liver function of unknown aetiology. Six months after surgery, follow-up MRI of the liver demonstrated three small lesions in segment I, IVa and VII-VIII consistent with metastatic disease. The case was reviewed at the multidisciplinary team meeting, where the decision was made to proceed with CAS-One IR guided microwave ablation.
Planning of the three lesions
3D visualization of all three lesions with planned trajectories, including needle-eye–view planning of the long trajectory to the segment I lesion
Verification of all three needles demonstrating minimal (2mm, 1mm, 3mm) deviation across trajectories
AblaSure® shows lesion and margin coverage of the caudate lesion
1st AblaSure result of the second lesion which needed a reablation
Planning of the re-ablation switching to 140W instead of 100W on initial burn to counter the heat-sink from the hepatic branch.
Final AblaSure result
AblaSure shows excellent lesion and margin coverage of the third lesion
Name: Dr. Naomi Hersey
Institution: Sheffield Teaching Hospitals NHS Trust
Patient age and sex: Male, 74 years-old
Initial condition and Imaging:
- May 2025 patient was diagnosed with a primary rectal tumor, T3N1M0
- Underwent abdomino-perineal resection two months later
- Not eligible for adjuvant chemotherapy due to deranged liver function of unknown aetiology
- Six-month follow-up MRI of the liver shows three metastases: 9mm lesion in segment I, 16mm lesion in segment IVa abutting the middle hepatic vein and a 15mm lesion in segment VII-VIII
- Case was discussed at the MDT meeting and decision was made to perform MWA of all three lesions with CAS-One IR
Treatment:
- The procedure was performed under GA to ensure optimal respiratory control
- MW was performed using the AngioDynamics Solero probe
- All three lesions were planned on the initial pre-ablation scan. After each ablation, the ablation zones were assessed using AblaSure®
- The challenging segment I lesion was treated first and targeted at a depth of approximately 19cm, with only 2mm of lateral deviation. The remaining two lesions were subsequently treated with millimetric precision. Only the third lesion required a re-ablation, due to heat-sink from hepatic vein, to ensure an optimal outcome.
- The patient remained well post procedure and was discharged home the same day.
Result and Conclusion
- One month follow-up MR shows no signs of disease recurrence or complication.
- Dr. Naomi Hersey said about this case: "The segment I lesion would have been nearly impossible for us to target without the advantages of the CAS-One IR system. Ablasure supported us to make real-time treatment decisions which optimised our likelihood of achieving complete ablation "